The STPS operates via a non-contacting magnetic proximity sensing device
combined with a simple electronic circuit resulting in the ability of producing
two separate and distinct logic level signals.

The STPS output signal is altered by the proximity of a separate ferro-magnetic
shunt, which is linked via the seat track. The logic signal produced is the
result of the proximity device being activated or deactivated.

When the seat is in the forward position zone of the track, the sensor
gives a low current (prohibit) signal. When the seat is in the rear positon
zone of the track, it gives a high current (enable) signal.